Effect of Single-liquid Acidic Primers on Bonding of a Composite Luting Agent Joined to a Prefabricated Alumina Coping Material

Purpose: The aim of this study was to assess the effect of acidic primers on adhesive bonding to prefabricated alumina material designed for fixed restorations.Methods: High-purity alumina disks (Procera AllCeram) were primed with one of the following materials: Acryl Bond, All Bond II Primer B, Alloy Primer, Estenia Opaque Primer, M.L. Primer, MR. Bond, and Super-Bond Liquid. The specimens were bonded with a dual-polymerizing luting composite (Variolink II). Unprimed specimen was prepared as the control. Bond strengths were determined both before and after thermocycling.Results: Average bond strength before thermocycling ranged from 12.0 to 39.1 MPa, whereas average bond strength after thermocycling varied from 0.0 to 26.9 MPa. The statistically highest post-thermocycling bond strength was obtained with the use of the Alloy Primer, Estenia Opaque Primer, and M.L. Primer agents.Conclusion: It can be concluded that the use of either the Estenia or Alloy Primer material, which contain 10-methacryloyloxydecyl dihydrogen phosphate (MDP), or the M.L. Primer, which contains 6-methacryloyloxyhexyl phosphonoacetate (6-MHPA), is recommended for bonding the Procera alumina copings with the Variolink II composite.